<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<body>
<br>
<form action="php15.php" method="post">
    <input type="text" name="code" onkeyup="if(this.value!=this.value.toUpperCase())this.value=this.value.toUpperCase()"><img alt="验证码" src="validationcode.php" onclick="this.src='validationcode.php?'+Math.random()"><br>
    <input type="submit" value="sub">
</form>
</body>

</html>